Centrifugal pumps used for recirculating water in water recreational apparatuses, such as spas, hot tubs, swimming pools and recirculating bathtubs, are prone to fouling and chemical build-up within the pump case. The principal problem area is around the seal which seals the impeller drive shaft to the pump case. Such fouling is the result of the precipitation of salts and other chemicals dissolved within the water.
Also, the seal which seals the impeller drive shaft to the pump case is prone to failure due to heat build-up at the seal.
Thus, there is a need for a centrifugal pump which avoids this problem in the prior art.